{"data":{"id":"us/21-cfr-558.485","jurisdiction":"us","citation":"21 CFR 558.485","heading":"Pyrantel.","body":"(a) Specifications. Type A medicated articles containing 48 or 80 grams per pound pyrantel tartrate.\n(b) Sponsors. See sponsors in § 510.600(c) of this chapter for use as follows:\n(1) No. 066104: 48 and 80 grams per pound for use as in paragraph (e)(1) of this section.\n(2) Nos. 017135 and 054771: 48 grams per pound for use as in paragraph (e)(2) of this section.\n(c) Related tolerances. See § 556.560 of this chapter.\n(d) Special considerations. (1) See § 500.25 of this chapter. Consult a veterinarian before using in severely debilitated animals.\n(2) Do not mix in Type B or Type C medicated feeds containing bentonite.\n(e) Conditions of use—(1) Swine—\nPyrantel grams/ton Indications for use Limitations Sponsor\n(i) 96 Swine: As an aid in the prevention of migration and establishment of large roundworm (Ascaris suum) infections; aid in the prevention of establishment of nodular worm (Oesophagostomum) infections Feed continuously as the sole ration in a Type C feed. Withdraw 24 hours prior to slaughter 066104\n(ii) 96 Swine: For the removal and control of large roundworm (Ascaris suum) infections Feed for 3 days as the sole ration in a Type C feed. Withdraw 24 hours prior to slaughter 066104\n(iii) 800 Swine: For the removal and control of large roundworm (Ascaris suum) and nodular worm (Oesophagostomum) infections Feed as the sole ration for a single therapeutic treatment in Type C feed at a rate of 1 lb of feed per 40 lb of body weight for animals up to 200 lb, and 5 lb of feed per head for animals 200 lb or over. Withdraw 24 hours prior to slaughter 066104\n(2) Horses—\nPyrantel tartrate g/ton Indications for use Limitation Sponsor\n(i) 120 to 1,200 to provide 1.2 mg/lb body weight For prevention of Strongylus vulgaris larval infections; control of adult large strongyles (S. vulgaris, and S. edentatus), adult and 4th stage larvae small strongyles (Cyathostomum spp., Cylicocyclus spp., Cylicostephanus spp., Cylicodontophorus spp., Poteriostomum spp., and Triodontophorus spp.), adult and 4th stage larvae pinworms (Oxyuris equi), and adult and 4th stage larvae ascarids (Parascaris equorum) Feed continuously as the horse's daily grain ration during the time that the animal is at risk of exposure to internal parasites. Do not use in horses intended for human consumption. Consult your veterinarian before using in severely debilitated animals and for assistance in the diagnosis, treatment, and control of parasitism 017135 054771\n(ii) Top dress medicated feed—(A) Proprietary Formulas. The following feed can be manufactured only per an approved proprietary formula and specifications:\nPyrantel tartrate amount Indications for use Limitations Sponsor\n(1) 9.6 g/lb to provide 1.2 mg/lb body weight Prevention of Strongylus vulgaris larval infections; control of adult large strongyles (S. vulgaris, and S. edentatus), adult and 4th stage larvae small strongyles (Cyathostomum spp., Cylicocyclus spp., Cylicostephanus spp., Cylicodontophorus spp., Poteriostomum spp., and Triodontophorus spp.), adult and 4th stage larvae pinworms (Oxyuris equi), and adult and 4th stage larvae ascarids (Parascaris equorum) Feed continuously as a top dress during the time that the animal is at risk of exposure to internal parasites. Do not use in horses intended for human consumption. Consult your veterinarian before using in severely debilitated animals and for assistance in the diagnosis, treatment, and control of parasitism 017135 054771\n(2) [Reserved].\n(B) [Reserved]\n(3) Pyrantel may also be used in combination with:\n(i) Carbadox as in § 558.115.\n(ii) Lincomycin as in § 558.325.\n(iii) Tylosin as in § 558.625.","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER E—ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS","PART 558—NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS","Subpart B—Specific New Animal Drugs for Use in Animal Feeds"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"e390d79e38d620d75e718dd0624c5f574b2ac875d34b96245ce96ba17ca3395e","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-558.470","next":"us/21-cfr-558.500"},"notice":"GroundRules: Original legal text. Not legal advice."}